Machine and method for coating with metal.



C. C. ROBERTS. MACHINE AND METHOD FOR COATING'WITH METAL.

APPLICATION FILED DEC- L6. 1916.

Pmtanwl Jan. 11, 1918.

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2 SHEETS-SHEET I CHARLES C. ROBER'IS C. C. RGBERTS,

METHOD FOR comma WITH METAL.

MACHINE AND APPLICATION FILED DEC. 16- IBIS-- mma m 1 1918.

2 SHEETS-SHEET?- C HARLes G. R Gama-rs CHARLES C. ROBERTS, OF ANSONIA, CONNECTICUT.

MACHINE AND METHOD FOR COATING WITH METAL.

Specification of Letters Patent.

Patented Jan. 1, 1919.

Application filed December 16, 1916. Serial No. 137,843.

To all whom it may concern:

Be it known that I, CHARLES C. ROBERTS, a citizen of the United States, residing at Ansonia, in the county of New Haven and State of Connecticut, have invented a certain new and useful Improvement in Machines and Methods for Coating with Metal, of which the following is a specification.

This invention relates to tinning machines and embodies an organization of elements which have been particularly devised for tinning metal sheets on one side though capable of arrangement to tin the sheets on both sides.

In referring to the invention as particularly relating to tinning machines it should not be considered that such machine is limited in its use for tinning sheets or plates of metal, as the machine may be employed with facility for coating sheets or plates with materials other than tin; and in the subjoined description the operation of tinning sheets which will be particularly described is only intended to demonstrate one of the practical functions of the mechanism embodying the features of the invention.

In the drawings:

Figure 1 is a longitudinal, sectional view of the machine;

Fig. 2, a transverse sectional view;

Figs. 3 to 6 inclusive, detail views of modifications, and

Figs. 7 and 8 detail views of a further modification.

My invention is an improvement on that illustrated and described in my Patent No. 911613, granted February 9, 1909, for tinning or coating machines in which the, sheet to be tinned is held depressed in a tinning bath by a rotatable member. In the present application the sheet to be tinned may be held depressed in the tinning bath by a non-' rotatable member. Outside of the tinning devices proper or the means for guiding the sheet to be tinned through the bath I may utilize any of the well known feeding, scouring, fiuxing, driving devices, etc., which are suitable to be adapted to a machine of this type, particular reference being made to the details of my Letters Patent above mentioned and my Letters Patent No. 780383 granted January 17, 1905, for tinning machines and to my pending application Serial No. 854361, filed July 31, 1914, for tinning machines. During the normal operation of the machine disclosed herein the metal sheet is uncoiled and advanced successively between scouring brushes, (not shown) over flux applying brushes, over heated drums and through a tinning bath. Then the sheet is advanced upwardly and engaged by wiping brushes after which it passes over a guide roller or drum and downwardly to a receiving reel or drum. The several parts of the machine are mounted in a suitable frame 2 supported by legs 3, 3 and carrying a depending shaft hanger 4. The front end of the machine is provided with a pair of feed rolls 5, 5. Immediately beyond the feed rolls are a pair of acid brushes 6,6 mounted to revolve in an acid receptacle 7 Between and above these brushes is a guide roller 8. Immediately beyond the acid brushes are the heating drums 9, 9 through which pass gas pipes 10, 10 provided with suitable burners (not shown). Between and above the heating drums 9, 9 is a guide roller 11 which together with the guide roller 8 and the feed rolls 5, 5 serve to maintain the direction of the advancing metal sheet in a horizontal plane 1n contact with the acid brushes and heating drums respectively. All of the revolving parts just described may be either connected up to suitable driving mechanism to be positively rotated or they may run idle with the advancing sheet. Immediately beyond and below the heating drums 9, 9 is a tinning bath the details of which will hereinafter be described. After leaving the heating drums the advancing sheet passes into and out of the bath and is held depressed in the bath by a guide or shoe 12. a

The sheet after passing through the bath under this shoe advances upwardly over the wiping brushes 13, 13 between and above which is a guide roller 14. Then the advancing sheet passes over the drum or roller 15 and downwardly where it is coiled around the reel 16 which latter if desired may be connected up to a power shaft and thus serve to pull the metal sheet through the machine. I/Vith the exception of the heating drums 9,9, and the guide shoe 12 the machine thus far described is old and well known and is disclosed herein merely for the purpose of showing the essential details of one machine in which my invention may be embodied. I will now describe the devices which enable me to guide the sheet through the tinning bath without permitting the molten tin to come in contact with the upper surface of the sheet.

Below and between the heating drums 10, 10 and the wiping brushes 13, 13 is a pot or receptacle 17 mounted over a suitable heater or furnace 18 which maintains the contents of the pot in proper fluid condition. This pot 17 is of a width greater than the Width of the widest sheet to be tinned and has mounted on its side walls clamping straps 19, 19 respective]y, the upper faces 20, 20 of which are curved on an arc and circumferentially recessed to form grooves 21, 21. These clamping straps 19, 19 are arranged to be lifted out of the bath to a position above the pot by the rods 22, 22 attached at their upper extremities to counter-weights 23, 23 mounted on suitable rods pivoted to the sides of the frame. These counterweights normally hold the clamping straps in their elevated position when all weight or load on these latter is released. Cooperaating with the upper faces 20, 20 of the straps 19, 19 are rotatable clamping collars 24. 24 provided on their peripheral portions with circumferential wedges 25, 25 respectively. These wedges 25, 25 cooperate with the grooves 21, 21 to grip the side edges of the sheet as it passes through the bath in the pot 17 in a manner which will be hereinafter described. Each collar 24 is mounted on a shaft 26 which latter is journaled in a hanger 27 at the lower extremity of a rack 28 passing through bushings 29 and 30 in the frame 2. Meshing with each rack 28 is a pinion 31 mounted on a shaft 32 journaled in the shaft hanger 4. Both racks and pinions may be operated independently of each other but I have shown the pinions mounted on the same shaft each end of which contains a crank 33 so that both clamping collars 24, 24 may be lifted simultaneously out of the bath and engagement with the clamping straps 19, 19. The clamping collars 24, 24 may run idle with the advancing sheet or be positively rotated by the pulleys 34, 34 or by connecting the same up to the driving gear in any other suitable manner. Between the clamping collars 24, 24 and having its under side concentric with the circumferential face portions of the collars is the shoe 12. This shoe is preferably, though not necessarily, made with an interior chamber 35, which latter is provided with a suitable heater 36 to which gas may be fed by a flexible pipe 37 connected up to a port 38 in the top wall of the shoe. The shoe like the clamping collars and clamping straps may also be lifted out of the pot 17 by means of cams 39, 39 operating in collars 40, 40 attached to the upper extremity of rods 41, 41 which latter are bolted at their lower extremities to flanges 42, 42 formed on the top of the shoe 12. The cams 39, 39 are carried by a shaft 43 journaled in theshaft hanger 4 and having one of its extrenuties provided with a handle 44. Theclamning straps 19,

19 are preferably adjustably mounted transversely of the pot by connecting them to bolts 45, 45 mounted in slots one of which is shown at 46 in the cross bars 47, 47 which latter are carried by the lifting bars 22, 22 attached to the counter-weights. The clamping collars 24, 24 are preferably made correspondingly adjustable with the clamping straps by fastening them to their respective shafts26, 26 by means of the bolted collars 48, 48. The limit -of the upward movement of the clamping straps'19, 19 is effected by means of the adjustable collars 49, 49 mounted on the rods 22, 22 contacting with the lugs 50, 50 projecting from the sides of the frame. Sometimes it may happen, especially in the case of narrow sheets, that the latter will be advanced underthe guide shoe without touching the same, thus leaving a clearance between the shoe and the upper face of the sheet. In such a case the sheet is guided around the under side of the shoe by the engaging portions of the clamping straps and collars. In the ease of tinning wider sheets, however, the guide shoe is necessarily employed to prevent the buckling of the sheets between their side edges. In order to practically plate sheet metal it is necessary that means should be taken to prevent the accumulation of dross on the surface of the tinning bath so that the sheet will not pick up the dross during the tinning operation. To effect this result I maintain the temperature on the surface of the bath where the sheet passes into and out of the same at a very high point. To accomplish this I heat the sheet before it enters the bath, preferably by means of drums and I also heat the (pposite surface of the sheet from that which is in contact with the bath, preferably by introducing a heater into the guide shoe. In. this manner I not only maintain the bath at a high temperature, but

- also by external heating agencies maintain the sheet at a high temperature while the M same is being plated. This is a Very important feature of my invention since ordinarily the running of a relatively cold sheet through a heated bath turns out an imperfect product.

In the embodiment of my invention disclosed herein I have shown a machine in operation for tinning the under side of the sheet, but the various heating instrumentalities, together with the means for preventing the bath from flowing around the side edges of the sheet, may be employed to advantage in machines for tinning the upper side of the sheet, as disclosed in my application Serial Number 854364 filed July 31, 1914 for tinning machines, since the broad feature of my invention resides in maintaining one or both sides of the sheet in a heated condition during the plating operation.

The machine is shown in operation tinning the under side of the copper sheet 51, the forward edge 52 of which is attached to a bar 53 set in a transversely disposed recess in the winding drum 16 on which the sheet is being wound. Before starting the machine the clamping collars 24, 24 and the shoe 12 are elevated to a position clear of the bath. When the shoe and collars are in this position the load on the clamping straps 19, 19 is released and the latter are also elevated clear of the bath due to the action of the ounter-weights 23, 23, but to a position below the shoe and clamping collars. The forward edge 52 of the metal sheet is then passed between the feed rolls 5, 5, under the guide rollers 8, 11, over the acid brushes 6, 6 and heating drums 9, 9, under the elevated shoe and clamping collars, under the guide roller 14, over the wiping brushes 13, 13 and over the drum 15. The edge 52 of the sheet is then passed through the slot in the bar 53 and the latter dropped into the recess in the winding drum 16. The clamping straps 19, 19 and thevclamping collars 24, 24 are then adjusted transversely of the sheet so that the outer faces of the collars 24, 24 are in vertical planes passing through the side edges of the sheet. The clamping collars 24, 24 are then lowered into the bath, the weight of the same being suflicient to overcome the counter-weights 23, 23 so that the clamping straps 19, 19 and the sheet 51 are simultaneously depressed into the bath. In this position the side edges of the sheet are gripped between the wedges 25, 25 on the clamping collars and the grooves 21, 21 in the clamping straps. The clamping collars 24, 24 thus serve as bulkheads in the bath and prevent the molten metal from flowing over the side edges and coming into contact with the top surface of the sheet. The shoe 12 is then lowered into the bath, its under surface serving to hold the body portion of the sheet depressed and to prevent the sheet from buckling. Power is then applied to the winding drum 16 which latter pulls the sheet through the machine so that its side edges slide through the grooves 21, 21 in the clamping straps, the wedges 25, 25 on the clamping collars being rotated with the sheet. In this manner I eflect a fluid-tight joint .at the edges of the sheet below the surface of the bath which prevents the coating material from flowing over the edges of the sheet. The under surface of the sheet 51 after it is coated with tin by passing in contact with the molten metal is wiped by the brushes 13, 13 which serve to spread the tin uniformly over the sheet and remove any surplus. Since the revolving clamping collars 24, 24 travel.with the sheet they serve to relieve the friction between the latter .and the grooves 21, 21. It is not necessary, however, that the clamping collars should revolve with the sheet since they need not revolve at all, and if desired may be rigidly attached to, or form a part of the guiding shoe, as shown in Figs. 3 and 4 in which the shoe 60 is provided with concentric wedges 61, 61 at its extremities, which latter coiiperate with the grooves 21, 21 to grip the side edges of the sheet. In such a case, however, the frictional resistance offered to the sheet is greater than in the case of revolving collars but is not of suflicient moment to interfere with the operation of the machine. I do not desire it to be understood, however, that my machine is confined to cotiperating wedges and grooves for gripping the side edges of the sheet since my invention broadly comprehends any means for forming a fluid-tight joint at the side edges of the sheet in a bath. Neither is it necessary that the joint should be effected by two elements since the same may be effected by a single element as is evidenced in the modi- I fications shown in Figs. 5 and 6 in which the side edges of the sheet 51 slide through the arc-shaped grooves 62 in the inner opposite faces of the plates 63, 63 which latter are yieldingly mounted by means of springs 64 in the side walls of the brackets 65, 65. Since the plates 63 are yieldingly mounted they are held against the edges of the sheet under tension being spread apart by clipped corners of the forward edge of the sheet when the latter is fed between them.

WVhile in the various modifications above 911,613 above referred'to is that the rigid I shoe does not tend to cool the bath by successively exposing its hottest side as in the case of a rotating drum.

In the modifications shown in Figs. 7 and 8 I have shown an internally heated rotatable guide. IVhile the guide may be integral with the clamping collars or mounted on the same shaft therewith yet I prefer to have the guide in the form of a rotatable drum 66 having hollow trunnions 67 67 seated in bearings 68, 68 carried by the lower 3 extremities of the rods 69, 69 which latter are connected to any suitable elevating mechanism, as for instance the rods 41, 41 in Figs. 1 and 2. Passing through the hollow trunnions 67, 67 is a gas pipe 70 provided with suitable burners 71, 71. This pipe 70 is connected to the flexible feed pipe 72.

The drum 66 may be lowered into the bath between the clamping collars occupying the same relative position thereto as does the shoe 12 shown in Figs. 1 and 2.

In all of the forms above described it is obvious that I may utilize any of the well known forms of heaters, in practice the preferred form being of the blow-pipe type. It is to be further understood that except where the clamping collars are rotatable the curvature of the under surface of the guide or shoe need not necessarily be on a circle as shown since the cross section of the shoe may be of any suitable contour so long as it depresses or guides the sheet through the bath. I have shown the under surface of the guide shoes taken on a very small circle for the convenience of illustration, but may say that in practice it is preferable to have the surface taken on a very large circle so that the depression of the sheet into the bath is very slight yet the length of travel of the sheet through the bath is relatively great.

While the machine herein illustrated and described embodies the preferred form of my invention it is obvious that the same is susceptible to such modification as may fairly come within the scope of the appended claims.

Having now described my invention what I claim and desire to protect by Letters Patent is:

1. In a machine for coating sheet material on one side, a receptacle for the tinning material, sheet advancing means, non-rotatable means for guiding the advancing sheet into and out of the tinning receptacle and means which engage the edges of the advancing sheet during the tinning operation to prevent the tinning material from flowing over the edges of the sheet.

2. In a machine of the class described a receptacle for tinning material, a vertically movable means for guiding an advancing sheet into and out of said receptacle and devices vertically movable independent of said guiding means for engaging the side edges of the sheet Within said receptacle to prevent the tinning material from flowing over the side edges of the sheet.

3. In a machine for plating sheet metal on one side a non-rotatable guide shoe provided with a heater, means for advancing the sheet under said shoe, means for maintaining a plating bath on the under side of said sheet and means for engaging the side edges of the sheet within the bath to prevent the plating material from flowing over said side edges.

4. In a machine for plating sheet metal on one side a tinning bath, a sheet-depressing and non-rotatable guide shoe arranged over the bath, the said shoe being provided with a heater, and means for engaging the side edges of the sheet within the bath to prevent the plating material from flowing over the said side edges.

5. In a machine of the class described a tinning bath, means for depressing the sheet into the bath and means operating independently of said depressing means for engaging the side edges of the sheet within the bath to prevent the plating material from flowing over the said side edges.

6. The method of plating sheet metal on one side which conslsts in advancing the metal in a heated condition, maintaining a tinning bath in contact with one side of said metal and preventing the bath from coming in contact with the opposite side of said metal.

7. The method of plating sheet metal on one side which consists in applying heat to the advancing metal and maintaining the metal in a heated condition while a tinning bath is applied to one side of said metal.

8. The method of plating sheet metal on one side Whichconsists in maintaining a tinning bath in contact with one side of the advancing metal and applying heat to that portion of the metal which is in contact with the tinning bath.

9. The method of plating sheet metal on one side which consists in maintaining a tinning bath in contact with one side of the advancing metal and applying heat to the opposite side of that portion of the metal which is in contact with the tinning bath.

In witness whereof I have hereunto set my hand on this 11th day of December 1916.

CHARLES C. ROBERTS.

Witnesses:

WALTER A. HOLDEN, BEATRICE E. GATES. 

